3.6 Assessment of PEG-FGF2 conjugates on skin wound healingin vivo
To confirm the positive wound healing effects of PEG-FGF2 conjugatesin vivo , wound closure was measured at days 0, 3, 5, and 7. These PEF-FGF2 conjugates showed a certain function of wound healing compared with the PBS control. Consistent with our in vitro results, topical administration of 100 ng compound 6 significantly accelerated wound healing compared to PBS treatment over the course of the healing process (Figure 7A ). Quantitatively evaluation of wound healing rate revealed that compound 6 was more effective in wound healing compared to FGF2 (Figure 7B ).
The pathological morphology and diameters of cutaneous wounds at day 7 after surgery were assessed with Hematoxylin and Eosin (H&E) staining. Wounds treated with compound 6 showed increased healing and shorter diameter. This result further confirms the effectiveness of compound 6 in cutaneous wound healing (Figure 7C ). Collagen deposition after treatments was also detected by Masson’s trichrome staining. As shown in Figure 7 D-E , different degrees of collagen deposition were observed for these compounds. Sections of wounds treated by compound 6 exhibited significantly higher collagen deposition compared with wounds treated with unmodified FGF2, indicating the improved therapeutic effect of compound 6 . However, wound sections of compounds 5 and 7 exhibited very little collagen deposition, consistent with the results of H&E staining. The results together demonstrate that compound 6 is more effective in promoting cutaneous wound healing in vivo .